No barrel temp and head temp are air cooled no oil involved. Well there is oil but only to stop the Piston rings welding themselves to the barrels the only oil in the heads is from the pushrods a tiny amount. You will want a deap sump of some kind as it will sit lower and have cooling air blowing below it. UK driven bus thats not stock. Full flow filter for oil Deep sump for extra oil = more cooling volume. Twin carbs Oil temp sender Stock flywheel and clutch. Crank case breather if the build requirements deem one Proper exhaust vintage speed ftw. Some have oil coolers (MikedJames I think)
We have a 1776 with twin dellorto 34frd carbs. Everythibg else is standard, heads, cam etc. We went to France a few years back with friends who had a 1641 single carb in their van and there was a noticeable difference on the long hills on the N roads over there. We'd keep steady at 55/60moh and they would get slower and slower. 1776cc - no firebreather but you'll be glad you've got those few extra CCs on the A361 to North Devon...
read page 17/18 of the guide I sent you, that talks about piston size and cylinder wall thickness, plus cooling fin surface area. 1914 may not be any additional cost to a 1776, but i don't think you will get the long life out of the engine that you require
Hi Paul, having read the guide that makes sense. ‘The maximum bore you can go to with the stock crankcase is 94mm. On the stock crank, this gives 1914cc. These have a good thick cylinder wall but their one disadvantage is that they have less fin area, therefore they can't dissipate heat as efficiently as the smaller sizes.’ and ‘For this reason, it is not recommended to use a 94mm piston and cylinder combination on a vehicle that is going to be used continually in conditions that require maximum cool- ing (e.g. regular medium to long journeys all year round).’
Yes I kept the cooling stock, except for a remote oil filter. Some plastic ears on the air intakes to help scoop the air in. It also had it on the CB 044 Big Valve heads. It felt very powerful and fine at low speed idle. Climbed up hills on the motorway easily and coped with a heavy bus loaded bus, but the temperature rose. I only used an oil dipstick saver to ping a red light on the dash to gauge as hirers were meant to slow down if they ever saw the red light flicker or come on. However one thought they would continue driving with a bright red light on the dash. Eventually the engine was dismantled and the very expensive 044 heads I brought had cracked between the valves. The van was only setup with a good spec engine because it was my personal van and I did not spare much expense.
Sock cooling? Do your socks get hot ? The thing that will bring it to life is the carburation. Twin carbs - ICTs will do - and a free flowing exhaust will let any engine breath properly. Personally, for longevity of the engine, I wouldn't go bigger than a 1776 on a type 1. It's not a hot rod. Needs to be reasonably understressed IMHO. Mine will happily romp up hills in third, fourth with a modest run.
The main thing to remember is the stock 1568 engine is quite happy with cooling and power at 3500 to 4000 rpm. The save my bug oil temperature flasher thing is pretty useless on a bus because it will be on solid at 115C and that is quite normal running. Its the 120 to 130C region you do not want. Its not good enough for a bus as you get used to the light flickering all the time.. Adding deep sumps is OK if your bus isnt lowered otherwise its one of the lowest bits of the bus. And mostly it slows down oil temperature rise. After 30 miles it wont be helping much. Cylinder heads do overheat regardless of the oil temperature, above 150C you get into cracking region, you really do need CHT gauges to see the scary numbers- climbing up some hills on the M4 towards Membury Services from the west are pretty harsh. In fact at high speed quite a lot of oil is thrown up the pushrod tubes from the crank , part filling the lower part of the covers so oil cooling is a factor in head cooling. Its amazing how fast oil comes out of that pinched seal... Head designs do make a difference- some stock heads also have a lot of casting flash blocking cooling air pathways. I have to say that the Preservation Parts engine has EMPI 040 stock sized heads which have some nice looking castings and clear paths between the fins, as well as slightly better sized exhaust ports ..and used AA barrels and pistons. The effect was that without me changing anything, a properly built new engine with a new aluminium case ran 10 degrees C cooler than my old engines. And now it has run in properly after 18000 miles it goes well too..
Mofoco also make heads with their own casting that claim improved cooling. Despite Roy being his own worst enemy on a forum there appears to be a consensus that they do cool perhaps 30% better which is a leap forward. I would be interested to know how well those heads work on a bus.
I have Mofoco heads on mine, oil temperatures are fine (touch wood), but engine also has full flow, external cooler and oil filter. I don't have a cht gauge so have no idea if they mean the heads are cooler than any other heads.
If you can cruise at 65mph or above without the oil temps rising and rising I'd say you have improved cooling.
Yes that is the case. A couple of summers ago we had that heat wave. There was one day when we were in the Netherlands and it was about 40c for some stupid reason we ended up driving furtjer that day than we did on the rest of the trip. The only thing that overheated was my amplifier under the back seat!
So I’ve been back in contact with the company and have discussed the 1776 and 1914 builds with. They know the engine build is for a bay, if I were to go with the 1914cc build they would adjust the compression ratio so that the engine runs cooler and believe it would be fine for a bay. I haven’t really made any decision which way to go yet, still thinking through all the options. The 1776cc build still seems like a good choice (or potentially 1835cc or 1914cc as they cost the same) , when you add on twin carbs, gearbox recondition then it all starts to add up and then my budget is probably spent. I am learning a lot and really appreciate all the good advice from everyone on this forum. I also like the sound of the 2100cc engine build paulcalf has, although I suspect the price is way more than I would like to spend. When you consider the actual increase in pure cc going from say the 1914cc (long life/94mm piston issue aside) to 2110cc it isn’t that large, presumably the actual performance in terms of torque produced would be considerably more given the stroke has increased?
The saying goes: There is no replacement for displacement. However I have no idea how much extra torque you might get from 1914cc to 2110cc Whether you go 1776cc, 1914cc*, or 2110cc the key will be to get a suitable combination of parts that compliment each other, built by someone who understands where you want the useable power, suitable compression ratio, engine temperature, engine life etc As you know i've had an excellent 1776cc that I was very happy with in terms of power etc etc Then a 1776cc that on paper should have been much better, but wasn't anywhere near as good as my original 1776cc in reality. Now I have a 2110cc that i'm very happy with (touch wood). I can't comment on a 1914cc* as i've no experience of one, I just know what i've read about piston size & cylinder wall thickness. Can you talk to the owner of a bus driving owner of a 1914cc built by your engine builder? @PanZer is/was yours a 1914cc, if so who built it and do you have the spec etc?
@KezBoy the prototype bay forum may have some people on with 1914cc engines. do a search on there. Shame @Alex (formerly) VW Heritage isn't kicking about,. In an old thread he said: 1915cc is a great size bus engine and costs no more than a 1776cc, either way will involve machining so costs should work out the same. I have lots of mates with this combo and it works great in a van. You will have to upgrade the exhaust and carbs at the same time, you'll end up running it lean and causing majort issues if you try running it from a standard single carb or even a 32/36 progressive. You could run it from a central single twin choke 40 IDF, but that will be a struggle to fit in a bay engine bay so a pair of twin 40's would be your best option. Exhaust wise a vinatge speed system is a good bet, they are good for 125Bhp so about right for a mild cam'd bus 1915cc https://thelatebay.com/index.php?threads/big-bore-kits-1776-vs-1914-opinions.44934/#post-786589
If you said 1500cc is to sort of base line cruise minimum, in terms of extra for hills and acceleration... 1600 has 100cc 1776 has 276cc 1835 has 335cc 1915 has 415cc 2110 has 610cc 2413 has 913cc That of course is maybe a silly way to look at it.
Sadly i’ve neither the knowledge nor experience to positively contribute. I think my original engine was bored out to 1955cc, with twin Kadron carbs. Normal oil cooler etc. Heavy crank. Normal Cam Shaft I think. Not an optimal compression ratio either. I didn’t seemingly have an overheating issue but my temperature gauge was taken from the Alternator stand. I was pretty sensible with it though and if it rose to 90• (I was told to never hit 100• on the setup) i’d slow down to 65mph and it would immediately cool down. Think the Crank Case is aluminium, not magnesium (or the other way round...whatever Americans do, as it came from California), if that makes a difference. I’ve still not got the rebuild in the Bay yet. Sent from my iPhone using Tapatalk
Yes, I came across that thread and was going to send a message to Alex but saw he hasn’t been online here for some time. I’m pretty convinced the company I talked to know’s what there doing and also knowing that I was keen on a good performing 1776 suggested the 1914 as another option, if tuned to run cooler it would be a good performing engine without any additional cost. I think I will investigate further on 1914cc engines in bays, would be really good to see what experiences people have had and the reliability.
So 1776, 1835 and 1915 will all be the same cost to build when upgrading my 1600. If I had a 1914 with lower compression ratio (to run cooler) then I guess it won’t perform as well as a 1914 with a normal compression ratio (what ever a normal compression ratio is, maybe around 8?). But the increase of a 1914 over a 1776 still sounds pretty good as long as the engine lasts. Going from 1914 to 2110 will require more machining, new crank, new fly wheel, rods, I think this adds up considerably, I think around an £800 or so, this seems like a lot of money for only a small increase in cc from 1914 to 2110. But I suspect it’s not as simple as that, I think the 2110 would perform much better than the cc difference implies. Maybe the comparison you make is more valid between engines with the same stroke? Would love if someone could explain as I know no nothing about engines.
This is the 110 cam one? And talk of lowering the compression to reduce heat? This is nonsense, the cam needs a certain amount of compression to run efficiently. If it's not running efficiently it'll make excess heat. Change the cam for a milder one yes along with a lower compression to suit. Here's the thing that engine builders face, THE main problem when making an engine "bigger than it was". The the compression ratio increases unless you carve out the heads or set an inefficient deck height with shims OR, THE BIG OR that is - see what the compression ratio works out to and fit a cam to suit - it was getting a new cam anyway so the result is - no extra work. Here's the numbers. Stock 1600 69mm crank 86.5mm pistons 1.5mm deck 50cc heads CR 7.7:1 1776cc 69mm crank 90.5mm pistons 1.5mm deck 50cc heads CR 8.4:1 - just about ok with stock cam, poss a mild one would be better 1915cc 69mm crank 94mm pistons 1.5mm deck 50cc heads CR 8.9:1 much too high for stock cam Without going into too much detail... Static CR as above is a simple calculation based on the volume of the cylinder at TDC and BDC to help build an engine. Where does the cam come into it? The inlet valve opens roughly at TDC, stays open to BDC sucking in fuel and shuts not at the bottom but part way up the compression stroke. This is because the inertia of the fuel keeps it filling the cylinder past BDC. The higher the revs the further past BDC this inertia filling is useful, but also the less stroke there is left to compress the fuel mix. Cams that shut the valve late to take advantage of the extra filling make their power at higher revs but also need a higher STATIC compression ratio to make up for the late valve closing. So you see lowering the CR for a late closing cam boogers it up and makes it gutless, so you put your foot down more, it burns more fuel and gets hot. Hopefully you also see what a simple solution fitting a cam with a later valve closing time is when faced with the naturally higher static CR from increasing the cc. Simple, but not correct for a heavy bus that needs power at ALL revs. the 1915 would need 61cc heads for a stock cam which is pushing it and would be a lot of work, days of work. The compromise would be a mild cam and partially enlarging the chamber to unshroud the valves to maybe 55cc and fit a mild cam. The answer is not to slap the heads on as is and a big cam. Sure it won't blow up, the numbers work, it would be fun in a lightweight Beetle, but it would be hell in a bus.
